Watt-hour meter base



my. bi/m5, BANK PRUTECTION :searcn HUGH? AND RELATED DEVICES.

une 6,1944. s. s. GREEN 2,350,395

' WATT-HOUR METER BASE Filed July 8, 1941 INVENTOR.

Sim-day 3'. Green BY 5 6 v I ATTORNEYS was MW "3 w )l t ma. SAFES', BANK PROTECWON ANS RELATED DEVES= Patented June 6, 1944 5651i Gil H66??? WATT-HOUR METER BASE Stanley S. Green, La Fayette, Ind., assignor to Duncan Electric Manufacturing Company, La Fayette, Ind., a corporation of Illinois Application. July 8, 1941, Serial No. 401,445

' but persons skilled in the art will readily perceive 4 Claims.

One of the problems in connection with watthour meter housings is to make tampering with the meter or its connections as difficult as possible. The meter base of the Holmes Patent No. 2,046,307 has proved very satisfactory in this regard, one outstanding advantage being the provision of double walls with the inner wall sloping. With this arrangement it was very diflicult to drill a fine hole through the meter since a drill, especially if fine enough not to leave a hole which would be readily detected, would be deflected by the slanting inner wall after passing through the outer wall and hence would not pass through the inner wall.

Under some conditions the use of the doublewalled structure may not be practicable. For example, with a cast-iron or ceramic base, the wall thickness may be such that within the standard outer dimensions of a base there would not be space for the two walls in addition to the structure desired within the base. In fact, even with conventional die-cast metal bases there would be some advantage in avoiding the double walls so as to have a maximum space available within the base when such space might be desired.

According to the present invention, a high degree of drill resistance is provided by a base which has only one integral wall but which has an auxiliary wall, or the equivalent of an inner wall, formed by a thin spring-steel insert normally lying close inside the outer wall of the base. Under pressure of the drill such an insert would yield so readily that drilling would be impossible unless the spring steel were pressed far enough to bear against some fixed member within the base, in which case the spring steel would usually be distorted or twisted so as to deflect the drill and hence keep the drill from passing through it. The same flexible steel insert may also extend a little beyond the plane of the gasket between the glass cover and the base so as to obstruct entry to the base through the gasket.

Additional objects and advantages of the invention will be apparent from the following description and from the drawing, in which:

Fig. 1 is a front elevation of a base shown more or less diagrammatically having therein the auxiliary spring-steel wall of this invention.

Fig. 2 is a vertical cross section taken approxi mately on the line 2-2 of Fig. 1.

Fig. 3 is a perspective view of the spring-steel other means for accomplishing the same results, and the claims are therefore to be construed as broadly as possible, consistent with the prior art.

The base II may be any type of base and may be formed of any material. It is illustrated as of a form which applicants assignee contemplates manufacturing out of porcelain. This form has the advantage of being difiicult to drill, even aside from the additionalprotection of the present invention.

The base is provided with a mounting plate l2 near the top thereof for mounting the measuring unit on the base and is likewise provided with mounting bushings I3 at a lower position to provide two more points of attachment for the measuring unit. At the bottom of the base may be a terminal chamber portion [4, from which terminal straps l6 may extend into the main meter compartment IT.

The side wall l8 of the base may be approximately perpendicular to the back wall l9 and is provided with a sealing rib 2| against which a gasket and cover, not shown, are secured. The cover may be secured in any conventional manner, as by bayonet clamps engaging lugs 22 which may be formed on or secured to the base in any desired manner.

The spring-steel auxiliary wall 26 preferably extends substantially as shown throughout all except the lower portion of the side wall l8. It need not extend along this lower portion because of the fact that drilling in this zone is prevented by the terminal chamber portion M, which, as seen in Fig. 2, projects forwardly of the wall IS.

The auxiliary wall 26 is preferably secured at a single point, as by securing tab 21 bent therefrom, which may be secured in place by a securing screw 28 for the measuring unit. It may be either under the securing member 29, forming a part of the unit, or on top of it.

The auxiliary wall is cut away, as at 3|, to lie over the formations 32 in which the bushings are secured. Of course, the bushings could be carried by pillars standing out from back wall It! and not connected otherwise to side wall [8, in which case the cutaway 3| would not be necessary. In the vicinity of the terminal straps I6 the end portions 33 of auxiliary wall 26 do not extend as deeply into the base as elsewhere since it is obviously desirable to keep the metal auxiliary wall 26 well spaced from all exposed conductors having a different electrical potential.

As seen best at the top of Fig. 2, the dimensions of the auxiliary wall 26 are such that it extends forwardly a substantial distance beyond the sealing rib 2i. With this preferred arrangement, anyone inserting a drill or wire through the gasket bearing against the rib 2| will find his wire or drill blocked by the auxiliary wall 26;

Because of the conventional use of a glass cover over the meter compartment H, the auxiliary wall 26 will be visible through the glass cover and its mere presence will discourage tampering with the meter.

The combination base comprising a singlewalled porcelain body portion and the auxiliary spring-steel inner wall is in some respects an ideal combination. It makes almost the maximum possible space available within a meter base having any given outer confines, and makes tampering with the meter by access through the base almost impossible since it is very difiicult to drill through the porcelain itself, and a person who succeeds in doing this merely encounters another wal1 which is diflicult either to drill through or to work around with a wire. Of course, the auxiliary wall 26 of this invention is also advantageous with any other bases. With a base having a thin single wall, still more space could be available than with the thick walls l8 and. I9 shown. With a double-walled base, the auxiliary wall 26 would represent a third barrier to tampering. It should be noted, incidentally, that the wall 26 would be of considerable utility even if it were rigid and rigidly mounted since it would still comprise one more barrier which had to be either drilled or worked around.

I claim:

1. A base for watt-hour meters and the like,

comprising a body portion having a back wall, a forwardly extending side wall integral therewith having a narrow sealing rib adapted for the sealing of a cover thereagainst, and an auxiliary wall formed of spring steel positioned closely inside the side wall, in part at least flexibly positioned a sealing rim adapted for the sealing of a cover thereagainst, and an auxiliary wall formed of steel positioned closely inside the side wall and extending rearwardly a substantial distance along the side wall from adjacent the sealing rim and extending forwardly of the sealing rim whereby it constitutes a barrier to attempts at entering the meter either through the side wall or adjacent the sealing rim, said auxiliary wall being formed of flexible but very hard metal and being flexibly mounted whereby sufl'icient drill pressure to cause an ordinary drill to bite into the metal will flex the auxiliary wall away from the side wall whereby any angularity in the disposition of the auxiliary wall when thus flexed will divert the drill.

3. A base for watt-hour meters and the like, comprising a porcelain body portion having a back wall, a forwardly extending side wall having a sealing rim adapted for the sealing of a cover thereagainst, and an auxiliary wall formed of steel positioned closely inside the side wall and extending, a substantial distance along the side wall whereby it constitutes a barrier to attempts at entering the meter through the side wall, said auxiliary wall being formed of flexible but very hard metal, having free ends and being flexibly mounted whereby sufiicient drill pressure to cause an ordinary drill to bite into the metal will flex the auxiliary wall away from the side wall whereby any angularity in the disposition of the auxiliary wall when thus flexed will divert the drill.

4. A base for watt-hour meters and the like, comprising a body portion having a back wall, a

; forwardly extending side wall having a sealing rim adapted for the sealing of a cover thereagainst, and an auxiliary wall formed of steel positioned closely inside the side wall and extending a substantial distance along the side wall whereby it constitutes a barrier to attempts at entering the meter through the side wall, said auxiliary wall being formed of flexible but very hard metal and being flexibly mounted whereby I sufficient drill pressure to cause an ordinary drill to bite into the metal will flex the auxiliary wall away from the side wall whereby any angularity in the disposition of the auxiliary wall when thus flexed will divert the drill.

STANLEY S. GREEN. 

